Hi folks!
I have both G2 and Ikarus Aerofly Pro and must say that in terms of sim-model and flight-behaviour the latter one is far superior to G2. In standard conditions like flying aerobatic manouvers at higher speeds, both Sims feel almost identical, but in terms of trying 3D, the fluid movements of the Plane, the reactions to every single Stick-input are just one thing - AWESOME

!
Graphic quality in G2 is far more better than AFP, but everyone who tried AFP won´t leave it!!
For my feeling, TR-ing and Hoovering in AFP seems a bit more difficult than in G2, in the latter one if you put the plane at the correct attitude, it TRs almost by its own, AFP models this aspect with more acuracy.
AFP seems to be far more popular in Europe, i know nobody owning G2 (but me), but a lot of guy with AFP. In the US, AFP seems to be quite exotic -
give it a try !
just my 2ct
best wishes
thomasK
edit: visit R. Matts homepage for information about 3D-ing with AFP:
http://www.matt-rc.li/englisch/news/flugsimulator.html